The present invention is a Continuation-In-Part of my co-pending application, entitled A Machine and Method for Mechanical Pickling of Wires with the Aid of Rolling, U.S. Ser. No. 832,064, filed Sept. 9, 1977.
This invention relates to a machine for cleaning small diameter wires, such as those from steelworks and intended for drawing, or previously drawn and annealed, and/or for subsequent treatment where full cleaning of the surface thereof is required. Usually the metal wires are covered with scales or slag, various oxides, calamine, etc., which should be removed to leave the wire fully cleaned before the successive drawing operations reduce the diameter to a desired size, or subsequent to the drawing operation.
The prior art provides two different series of cleaning or pickling operations, depending on the desired degree of cleaning or pickling. In the first instance, cleaning of the product from the steelworks is often mechanically performed by various systems of mechanical removal, depending on the type of material and shape thereof (such as wire, bar, ingot, sheet or plate, etc.). To this end, and particularly as far as wires are concerned, scaling machines are known, such as that disclosed in U.S. Pat. No. 2,242,024 (Dillon). According to this arrangement, toothed sheaves and gear wheels are provided by which metal wire passing therethrough is flexed and distorted so as to break up and separate the scales or slag and other surface impurities. Then a ball mill or brushes or other scraping devices are employed for fully separating the scales or slag and for more thorough cleaning of the wire.
Other systems previously known or experimented with comprise, grinding wheels of different types, jets of abrasive material, systems provided with a rotating cylinder containing pneumatic pressure abrasive materials, wide or cup brushes with the sides thereof perpendicular to the wire to be processed, and so on.
All of the above are specific mechanical type systems and processes which are advantageous for a first or rough cleaning of the wire, where the product thus obtained is used and where a full or thorough surface cleaning is not required. In these latter cases, the prior art provides the use of chemical pickling by means of baths in acidic or basic solutions performing a complete removal by chemical means of the oxide layer, among which is calamine, which may have remained adhered to the wire, notwithstanding the previous mechanical cleaning operation. The prior art often provides the use of chemical pickling following the mechanical cleaning and descaling, either because the latter is unable to provide a wire having its surface fully cleaned, or also because it would be wasteful to directly use a chemical pickling bath to remove the coarsest slag and surface impurities of the wire that could be also mechanically removed.
There are other prior art methods and systems for the cleaning of bars, ingots, tubes and the like, but which are completely unsuitable for application of thin wires (that is, of a diameter to about 10 mm), for example, such as those disclosed in U.S. Pat. Nos. 1,647,499 (Bly); 1,230,584 (Lally); and 3,780,552 (Staskiewicz).
The basic disadvantages of the prior art are mainly due to the impossibility of providing a thorough cleaning of the surface of thin wires by machines using sheaves and gear wheels or ball mills, as described in U.S. Pat. No. 2,242,024 (Dillon) or by using brushes or other scraper means. Particularly, the brushes are satisfactory for discrete cleaning on bars, tubes or products exhibiting a discrete surface on which a brush is capable of operating. However, in case of thin wires which are not quite straight or rectilinear and that may partly rotate about their own axis during the cleaning operations (as a result of the applied dragging force), or which may be also deformed at a given section thereof by the several operations to which it has been subjected; such known systems, and particularly the brushes hitherto used also in combination with other devices, are quite unsatisfactory.